The essence of the counter inference is intelligence competition and critical decision making that will result in chained reactions in an open system environment. Intelligent agents are capable of not only carrying out negotiations but also playing games. A negotiation could have win-win (or lose-lose) outcomes while a game may result in win-lose situations. This paper is to propose the counter inference as a unified reasoning paradigm to allow intelligent agents to execute reasoning tasks in either cooperative or non-cooperative ways. Based on logic theory, we will discuss a framework of the counter inference. Some examples of the counter inference will also be given to illustrate its reasoning scenario.